Don't get me wrong - the Bucs D stinks. Its one of the worst in the NFL. And Smith was hurting, Duffner is an immediate upgrade.
But you have to know that and play your offense and game managment accordingly. And Winston and Koetter have refused
The Bucs O has 4 INTs and (including a pic 6) and the Bucs have "only" given up 30 points. That's not great but it's also not terrible. Perhaps a bigger problem than the points is the lack of TOs (which help reduce the points). Yet you have:
1) Koetter continuously wanting to kick field goals with goal-to-go and on 4th-and-2.
This is stupid. You have to lean into your strength: the offense. You know, unfortunately, your D will give up lots of points. Which means you need to give yourself every chance to win by scoring as many points as possible. And Koetter refuses. This is a big difference between a winning coach (like Pederson) and Koetter.
2) Winston's TOs
This one is more obvious. You're putting a bad D on the field too often and on short fields.
When you have a bad defense its even more important to limit turnovers as they hurt more. If you had the Chicago D the opposing team might score 1/3 drives. But with the Bucs D its probably 2/3. So every turnover is more costly to the team. And the Bucs and Winston know that, which means you have to be even SMARTER with the football than normal.
Conclusion: "'ll also say that while everyone is saying "if this team had even an average D" they'd be in the playoffs." Well, the Bucs did have an average D in 2015 and 2016.